Neor Profile SQL - MySQL free GUI tool for profiling SQL queries.
Open DBDiff - A database comparison tool for Microsoft SQL Server 2005+ that reports schema differences and...
Devart Studio for SQL Server - dbForge Studio for SQL Server is a powerful SQL Server GUI Tool for SQL Server database management, administration, development, datareporting and analysis.
Redgate SQL Data Compare - Use Redgate SQL Data Compare to compare and synchronize static, lookup, and reference data in your SQL Server database - try it free
Sql Server Profiler - SQL Server Profiler shows how SQL Server resolves queries internally.
a7 SqlTools - Tools for MS Sql management with search, explore and comparison functionality.